The reflex that causes an infant to suck when the roof of the mouth is touched is called the reflex.

The reflex that causes an infant to suck when the roof of the mouth is touched is called the sucking reflex. This reflex develops when a baby is still in the womb (earliest in week 32 of pregnancy and it is generally fully developed by week 36 of pregnancy). Suction helps keep the breast in the baby’s mouth during the process through negative pressure.